This application claims the priority of International Application No. PCT/DE2004/001654, filed Jul. 23, 2004, and German Patent Document No. 103 36 587.7, filed Aug. 8, 2003, the disclosures of which are expressly incorporated by reference herein.
The present invention relates to a rotor blade for gas turbine rotors. In addition the invention relates to a method for manufacturing gas turbine rotors having integral blading.
Gas turbine rotors having integral blading are identified as blisks or blings according to whether they have a disk-shaped rotor and/or rotor mount or a ring-shaped rotor and/or rotor mount. Disk-shaped gas turbine rotors having integral blading are referred to by the term blisk (bladed disk) and ring-shaped gas turbine rotors having integral blading are referred to by the term bling (bladed ring).
It is known from the related art that gas turbine rotors having integral blading can be manufactured by the so-called method of milling from a solid block. Milling from a solid block is used mainly to manufacture relatively small gas turbine rotors. For example, milling from a solid block is suitable in particular for mass production of blisks or blings having relatively small titanium blade pans. Milling blisks or blings from a nickel alloy is problematical because of the poor workability of this material.
Another method of manufacturing gas turbine rotors having integral blading, which is known from the related art, involves joining finished rotor blades to the rotor mount, i.e., the hub, by so-called linear friction welding. In linear friction welding, one of the parts to be joined is clamped in a fixed position while the other part is oscillated linearly and pressed with pressure against the fixedly clamped part. The friction heats up the area of the weld zone to a forging temperature and the pressure results in the development of a welding bulge in the joining area. In the manufacture of relatively large gas turbine rotors, i.e., gas turbine rotors having relatively large blade pans, linear friction welding is more economical and less expensive than milling from a solid block.
Against this background, the problem on which the present invention is based is to propose a novel rotor blade for gas turbine rotors and a novel method for manufacturing gas turbine rotors having integral blading.
According to this invention, the blade footing of the rotor blades is adjusted so that the blade footing is designed with a V-shaped cross section in at least some portions in order to manufacture a gas turbine rotor having integral blading by means of capacitor discharge welding, in particular capacitor discharge stud welding.
According to an advantageous refinement of the present invention, the footing of the blade has a cross section adapted to the introduction of pressure forces in an area situated between the blade pan and the area designed with the V-shaped cross section. The blade pan preferably has a protrusion running in the longitudinal direction of the blade pan or at least a groove running in the longitudinal direction in order to introduce the pressure forces.
Preferred refinements of the present invention are derived from the following description.